I would think you would save money in the long term if you buy a great used bike, but getting the best possible one you can. Investing $400-$500 in a new bike which you might replace in a couple of years doesn't make financial sense when you can get a really nice used bike for the same amount, but end up using it for many more years down the road.

That way your husband can have the satisfaction of getting you the best bike possible (within budget), you get a reasonably priced bike that will put you at a performance advantage, and your accountant likes that your purchase will last for years to come.

When my wife was riding a compromise, she did not feel confident nor comfortable riding. When I replaced that compromise with a bike I should have gotten in the first place, she is much more comfortable riding and has used the bike much more; she actually looks forward to riding.

My 0.02 cents